Increasingly stringent environmental demands are encouraging the automotive industry to look for ways of producing lighter and more fuel-efficient cars. Using new technology, the VEK Project (so called because of its focus on the weight optimization of energy-absorbing components in the vehicle industry) has developed a bumper in high-performance stainless steel that is 26 percent lighter. Innovatum, Saab Automobile, Outokumpu Stainless, Finnveden Metal Structures and Epsilon are just some of the companies that have taken part in the project.

Higher fuel prices and requirements for reduced carbon dioxide emissions have put automotive manufacturers under increasing pressure to produce lighter, more fuel-efficient cars. Using a high-performance stainless steel, the VEK Project has succeeded in developing a bumper system that at no extra cost and without sacrificing performance is 26 percent lighter than existing bumpers. The greatest weight reduction has been achieved in the collision boxes.

“In terms of our design specifications, we modeled our work on the bumper system used by the Saab 9-3 Sport Sedan, which is widely regarded as one of the best in the world. The results obtained from the VEK Project will be one of the factors taken into consideration when choosing future design concepts for the production of new cars throughout the GM Group,” says Jonas Adolfsson of SAAB Automobile in Trollhättan in Sweden, who is project manager for the VEK Project.

An interactive network including Saab Automobile, Outokumpu Stainless, Epsilon , Finnveden Metal Structures and Innovatum (project owner), together with a further 15 parties, has been involved in the cooperation to develop prototypes, carry out actual collision testing and develop simulation models and production tooling. The project, which began in the autumn of 2002 and is due to be completed in late 2004/early 2005 has been financed in part by the 2nd EU frame program and Vinnova, the Swedish Agency for Innovation Systems, as part of the “Green Car” initiative for environmentally-friendly cars.

The ultra high-strength stainless steel grade used in the prototypes, HyTens, has been developed by Outokumpu Stainless AB. One of the finesses with HyTens is that the properties and weight of the components can be optimized by interactively controlling the strength when the component is shaped.

“This has been an extremely rewarding and successful cooperation, which has provided us with a much broader knowledge of the design, simulation and production considerations involved with energy-absorbing components. The bumpers are one of the most difficult parts to design , so naturally, the experience and knowledge we have gained can also be put to good use for other steel components in vehicles,” says Eric Sörqvist at Prinox in Trollhättan, a part of Outokumpu Stainless.

The potential environmental benefits of manufacturing cars using a lightweight design that involves high-performance steel are enormous. A preliminary study suggests a potential overall weight saving of 35-40 kg per car. If Saab produces 70 000 cars/year, the weight reduction corresponds to a saving of 2 500 tons a year. A rule of thumb is that a weight reduction of 10 percent can result in a 2.5 percent reduction in fuel consumption. This would correspond to a reduction in fuel consumption of 1.5 million liters per year, assuming mileage of 20 000 km/car/year. In five years, that amounts to some 7.5 million liters. This method also means that the components do not need to undergo surface treatment.

For further information, please contact:
Jonas Adolfsson at Chassis Design, Saab Automobile, Trollhättan, project manager, tel. +46 (0)520 85000
Eric Sörqvist, at Prinox, Outokumpu Stainless, Trollhättan, steering committee, tel. +46 (0)70 589 48 41.